print("Press Enter to allocate a big chunk of memory.");
<STDIN>;
@a = (0..100000);
print("Memory allocated.\n");
print("Press Enter to free it.");
<STDIN>;
undef @a;
print("Memory freed.\n");
print("Press Enter to exit perl.");
<STDIN>;

__END__
6,328K initially
8,332K after allocating
7,952K after freeing.